PSORIASIS – Severity and Types

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Psoriasis is one of the most common immune-mediated diseases world-wide. It is a chronic condition that waxes and wanes. Importantly it is not contagious but it can be an extremely painful, disfiguring and disabling condition for which there is no cure.

The exact causes of psoriasis have yet to be determined, however impairment of the immune system and genetics are known to play major roles in its development. When the immune system is somehow triggered it speeds up the growth cycle of skin cells among other immune reactions leading to a thickening of the skin, inflammation and excessive scaling.1

The prevalence of psoriasis in different populations varies between 0 and 12%, with estimates between 2 – 3% in most western populations. The prevalence in the northern most regions of the Russia and Norway ranges between 5–10% of the population and the highest 12% prevalence is found in the arctic population.2  In the U.S., prevalence ranges from 2.2% to 3.15% and the prevalence among African Americans is 1.3%. There is a low prevalence among North American Indians, Asians and Western Africans (0.3%). In Japan it is 0.1-0.2% of the population, in China 0.3% and is virtually undetected in Native South American Indians.3, 4, 5 Estimates of the prevalence of psoriasis in Australia ranges from 2.3% to 6.6% and in the U.K., the range was 1.3% to 2.6%.4,6  In Australia in the indigenous population it  occur rarely, with two recent Australian studies reporting small numbers of Indigenous patients in both the urban and rural environment presenting with psoriasis.7

What triggers psoriasis is a complex question and a large number of factors are involved. Genes are important: numerous family studies have provided compelling evidence of a genetic predisposition to psoriasis, although the inheritance pattern remains unclear. The condition will develop in up to 50% of the siblings of persons with psoriasis when both parents are affected, but prevalence falls to 16% when only one parent has psoriasis and falls further to only 8% percent if neither parent is affected.8 Environmental risk factors also play a role: bacterial and viral infections, stress, skin trauma, smoking and obesity have all been associated with the onset and exacerbation of psoriasis.9

The classification of severity is based on several dermatological markers. It often is a combination of a PASI (Psoriasis Area and Severity Index) score and a BSA (Body Surface Area) coverage factor.

A PASI score is used by dermatologist to measure the dermatological markers to determine the severity and extent of psoriasis, especially during a clinical trial. Four body areas, the head, the arms, the torso and the legs, are measured according to redness (erythema), thickness (Induration/Infiltration) and scaling (Desquamation) from 0 to 4. (See Chart)

% coverage of the body affected is also involved in the classification of the severity of psoriasis. The classification of mild psoriasis is made when symptoms affect less than 3% of the body surface. Moderate psoriasis covers 3% – 10% and the classification of severe indicates that symptoms affects more than 10% of the body, also the involvement of the hands, feet, facial, or genital regions, by which, despite involvement of a smaller BSA, the disease may interfere significantly with activities of daily life. This of course does not take into account the emotional impact that the condition has on the sufferer.9

Absent MildModerateSevereVery Severe
Redness / Erythemasevere_1

None


Score 1
severe_3
Score 2
severe_4

Score 3

Sev_1
Score 4
Thickness/

Hyperkeratosis

sev_2
None
sev_3
Score 1
Sev_4
Score 2
Sev_5
Score 3
Sev_6
Score 4
Scaling/DesquamationSev_7
None
Sev_8
Score 1
Sev_9
Score 2
Sev_10
Score 3
Sev_11

Score 4

Sev_12

Psoriasis can have a devastating impact on psychological well-being and social functioning, similar to that of cancer, arthritis, hypertension, heart disease, diabetes or depression. Most people with psoriasis suffer feelings of stigmatization because of their highly visible symptoms. This leads to feelings of social discrimination and alienation which compounds the feelings of anxiety and depression.9

Almost 90% of psoriasis sufferers have feelings of shame and embarrassment, 62% feel depressed, 58% suffer from anxiety, 44% feel that they have problems at work with most feeling that they are rejected for promotions, not accepted as part of the work group etc., 42% suffer from a lack of self-confidence due to their self-consciousness and 40% have difficulties in sexual relationships.10 

TYPES OF PSORIASIS

Psoriasis has been classified into several different types10, depending upon presentation, including:-

  • Plaque psoriasis or Psoriasis vulgaris (common type) – comprises approximately 90 percent of cases. Characterized by sharply demarcated erythematous silvery scaling plaques which most commonly occur on the extensor surface of the elbows, knees, scalp, sacral, and groin regions. The lesions are well-defined round or oval plaques that differ in size and in chronic plaque psoriasis that often coalesce to form very large, oddly shaped lesions covering large areas of the body.  Other involved areas include the ears, glans penis, perianal region, and sites of repeated trauma.
  • Scalp psoriasis is plaque psoriasis that is confined to the scalp, nape, forehead, sideburns, ears) the scalp lesions rarely extend > 2 cm beyond the hairline. Compared with plaque psoriasis elsewhere on the body, scalp involvement is frequently asymmetrical.
  • Guttate psoriasis – numerous small, red or salmon pink, drop-like spots which cover a large portion of the skin. Spots have fine, slivery scale. Lesions are usually located on the trunk, arms and legs. Usually proceeded by a bacterial streptococcal infection (strep throat, chronic tonsillitis) or a viral respiratory infection.
  • Flexural/intertriginous (Inverse psoriasis) – is located in the skin folds: i.e. armpits, under the breasts, skin folds around the groin and between the buttocks and in the skin fold of the obese. It is particularly subject to irritation from rubbing and sweating because of its location in the skin folds and tender areas. The plaques are thin, have minimal scale and a shiny surface commonly accompanied by secondary fissuring and/or maceration (the softening and breaking down of skin resulting from prolonged exposure to moisture). It is also prone to secondary infections such as tinea and candida.
  • Palmoplantar psoriasis – presenting as hyperkeratotic (thickened), red or yellowish, scaly plaques on the central palm or weight-bearing areas of the soles. The lesions are well demarcated and often accompanied by painful cracking and fissuring.
  • Palmoplantar pustulosis (PPP): is characterized by hyperkeratosis and clusters of pustules over the palms, and soles of hands and/or feet. These sterile pustules can remain as discrete pustules or may become confluent, producing lakes of pus which dry out, and the skin subsequently peels off, leaving a glazed, smooth erythematous surface. Quite often new crops of pustules will then appear.
  • Pustular psoriasis or Generalized Pustular psoriasis (von Zumbusch type) – Pustular psoriasis may be localized clusters of pinhead sized sterile pustules or as in the Generalized presentation – the skin becomes very red and tender and within hours, pinhead-sized pustules appear studding the erythematous back? These painful, sterile pustules may become confluent, producing lakes of pus. Subsequently, the pustules dry out, and the skin peels off, leaving a glazed, smooth erythematous surface on which new crops of pustules may appear. This is usually accompanied by a fever and systemic symptoms e.g. nausea, and may require the patient to be hospitalized.
  • Erythrodermic psoriasis – characterized by erythema, severe scaling, itching, and pain. This unstable psoriasis may some? times evolve to whole-body involvement that can lead to the inability to maintain homeostatic functions and often requires the patient to be hospitalized.
  • Nail psoriasis – affecting the nails of the fingers and/or toes, may affect only one or several nails. The most frequent signs of nail psoriasis are pitting and distal onycholysis. Clinical manifestations range from pitting, yellowish discoloration, and paronychia, to subungual hyperkeratosis, onycholysis, and severe onychodystrophy.
  • Psoriatic arthritis (PsA) a chronic inflammatory joint disease occurs in up to 39 % of patients with psoriasis. This type of arthritis can be slow to develop, with only mild symptoms or it can develop rapidly with extreme pain and characterized by focal bone erosions. PsA can be a severe form of arthritis with prognosis similar to that of rheumatoid arthritis

For more information on each classification of psoriasis refer to posts on each individual type.

REFERENCES

  • Višnja Milavec-Pureti?  et al.; Drug Induced Psoriasis; Acta Dermatovenerol Croat 2011;19(1):39-42
  • Bhalerao A., Bowcock A. M. ; The Genetics of Psoriasis: A Complex Disorder of the Skin and Immune System; Mol. Genet. (1998) 7 (10): 1537-1545 doi:10.1093/hmg/7.10.1537
  • Kuchekar A.B. et al.; Psoriasis: A comprehensive review; Int. J. of Pharm. & Life Sci. (IJPLS), Vol. 2, Issue 6: June: 2011, 857-877 857
  • Parisi R et al. Global epidemiology of psoriasis: A systemic review of incidence and prevalence. J Invest Dermatol 2012 Sep 27; [e-pub ahead of print]. (http://dx.doi.org/10.1038/jid.2012.339)
  • Menter A., Stoff B.; Psoriasis – Chapter 1 History, Epidemiology and Pathogenesis; 2010; Manson Publishing UK.
  • Parisi R. et al. Global Epidemiology of Psoriasis; Journal of Investigative Dermatology (2013), Volume 133
  • Heyes C. et al.; Non-infectious skin disease in Indigenous Australians; Australasian Journal of Dermatology (2014) 55, 176–184
  • Farber, E.M., Nall, L. and Watson, W. (1974) Natural history of psoriasis in 61 twin pairs. Arch. Dermatol., 109, 207–211.
  • Pelle Stolt, Maglia Rotta; Bringing Psoriasis into the Light; International Federation of Pharmaceutical Manufacturers & Associations; http://www.ifpma.org/fileadmin/content/Publication/2014/Psoriasis_Publication-Web.pdf
  • https://www.statista.com/statistics/409255/psoriasis-impact-on-individuals-physical-and-social-functioning/
  • Zangeneh F.Z., Shooshtary F.S.; Psoriasis — Types, Causes and Medication – Chapter 1; http://cdn.intechopen.com/pdfs-wm/44173.pdf

PSORIASIS and SMOKING

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Tobacco smoke contains numerous chemicals that exert inflammatory effects on the human body. Recent studies suggest that cigarette smoking may trigger the development of psoriasis through oxidative, inflammatory and genetic mechanisms. Smoking initiates formation of free radicals that stimulate cell signalling pathways active in psoriasis. Smoking damages the skin by increasing formation of reactive oxygen species (ROS) and decreasing the gene expression of antioxidants. Nicotine also stimulates innate immune cells integral to the pathogenesis of psoriasis. This perpetuates a cycle of chronic inflammation. Smoking also enhances expression of genes known to increase the risk of psoriasis.1,2,5

Research has found that increased smoking intensity corresponds to a higher risk of developing severe psoriasis whilst  longer cumulative duration of smoking (pack-years) increases the likelihood of developing psoriasis. The study also demonstrated a graded increase in psoriasis risk with increasing exposure to passive smoke.                              

In one study, researchers investigated the associations between smoking status, quantity,duration, and cessation and exposure to environmental tobacco smoke and the risk of incident psoriasis in a total population of 185,836 participants from the Nurses’ Health Study (NHS), the Nurses’ Health Study II (NHS II), and Health Professionals’ Follow-up Study (HPFS). They reported that in the NHS, 20% of the cases of incident psoriasis might have been prevented by the elimination of smoking. Similarly, the population-attributable risk was 15% in the NHS II and 19% in the HPFS. For all participants, 17.5% of the incidents of psoriasis were attributable to having ever smoked. Evidence from past association studies seemed to indicate a stronger association between smoking and psoriasis in women than in men.3

Research has also shown that the risk increases with the number of cigarettes smoked daily. Studies have shown that smoking more than 10 cigarettes per day by men who are psoriasis patients may be associated with a more severe expression of disease in their extremities. In addition, smoking among both men and women who are psoriasis patients has been shown to reduce improvement rates and hence difficulty in achieving remission during treatment.4 In a multicentre case-control study of 404 psoriasis patients and 616 controls, the risk for psoriasis was higher in smokers compared with non-smokers, and the association with smoking was stronger and more consistent among women than men. A particularly strong association was also found between smoking more than 15 cigarettes per day and Palmoplantar Pustular Psoriasis (PPP). Several observational and case-control studies have demonstrated up to 94% prevalence of tobacco use in patients with PPP.6 

Smoking

As tobacco smoking also interferes with the bodies immunity by allowing colonization by perio -dontopathic bacteria and by acting as a local irritant, researchers have hypothesized that smoking may act as a trigger or permissive factor of periodontal disease in patients suffering from psoriasis. In order to test this hypothesis, the prevalence and severity of periodontal disease, Researchers assessed a group of smoking and non-smoking psoriasis patients and a group of smoking and non-smoking psoriasis-free controls. In this study it was statistically shown that psoriasis patients who smoke are at an approximately sixfold higher risk of developing severe periodontal disease, as compared to psoriasis patients who do not smoke.7

Another interesting observation was the frequent coexistence of a smoking habit and alcohol consumption in patients with psoriasis. In the literature, alcohol consumption has been described as a factor responsible for triggering psoriasis, but it is said that smoking increases the risk of the onset of the disease. Previous studies have indicated that smokers who drink are twice as likely to develop the disease as non-smokers and non-drinkers.8,9

It is well recognized that stress and anxiety acts in both the initiation and exacerbation of psoriasis. Psychosocial stressors include acute negative life events or chronic strains and have been implicated as risk factors for tobacco use. Psychological stress may influence smoking behaviour (e.g., initiation, maintenance, and relapse) through a number of mechanisms. Specifically, smoking may function as a coping behaviour, whereby nicotine is used to self-medicate in response to stress; it is also possible that exposure to stress may result in diminished self-regulation to control the urge to smoke. Previous observational studies illustrate that acute stressful events and greater exposure to chronic stressors (e.g., related to work, finances, or relationships) are associated with higher smoking prevalence compared to persons who did not experience these stressors.10

So in summary, studies suggest that cigarette smoking may trigger the development of psoriasis through oxidative, inflammatory and genetic mechanisms. Furthermore, smoking is associated with the clinical severity of psoriasis. Smoking also contributes to higher morbidity and mortality from smoking related disorders in these patients. It is, therefore, advisable, if possible to quit smoking, or at the very least, keep your smoking to a minimum, preferably under 10 cigarettes a day. Try to adopt other mechanisms to cope with your stress and anxiety and it is suggested that you read our other blogs on “Simple Physical and Mental Relaxation Techniques”.  Using these techniques you may be able to reduce your stress and anxiety levels and this may allow you to cut down on the number of cigarettes you smoke.

Also read our blog “Psoriasis and Alcohol Intake”, “Stress, Anxiety, Depression and Psoriasis”, “Stressed about Psoriasis – Identify Your Stressors and Yours Stress Responses”, “Simple Physical Relaxation Techniques for Psoriasis Patients” and  “Simple Mental/Mind Relaxation Techniques Part 1 and Part 2”

REFERENCES

  • Armstrong AW, Armstrong EJ, Fuller EN, et al. Smoking and pathogenesis of psoriasis. Br J Dermatol 2011; 165: 1162-8.
  • Al-Rubaii A, Al-Ward N, Al-Waiz M. The age of onset of psoriasis and its relationship to smoking habits and stressful life events. Saudi Med J2003; 24:108.
  • Wenqing Li et al.; Smoking and Risk of Incident Psoriasis Among Women and Men in the United States: A Combined Analysis; American Journal of Epidemiology Advance Access published January 12, 2012; http://aje.oxfordjournals.org/content/early/2012/01/11/aje.kwr325.full.pdf+html
  • Behnam SM,Behnam SE, Koo JY.; Smoking and psoriasis.; Skinmed. 2005 May-Jun;4(3):174-6.
  • Armstrong AW, ; Psoriasis and smoking: a systematic review and meta-analysis; British Journal of DermatologyVolume 170, Issue 2, Article first published online: 18 FEB 2014
  • Freiman A. et al.; Cutaneous Effects of Smoking; Journal of Cutaneous Medicine and Surgery Volume 8 Number 6 December 2004
  • Antal M. et al.; Smoking as a Permissive Factor of Periodontal Disease in Psoriasis; PLOS ONE | www.plosone.org; March 2014 | Volume 9 | Issue 3 | e92333
  • Agnieszka B. Owczarczyk-Saczonek , Roman Nowicki; The association between smoking and the prevalence of metabolic syndrome and its components in patients with psoriasis aged 30 to 49 years; Postep Derm Alergol 2015; XXXII (5): 331–336 DOI: 10.5114/pdia.2015.54743
  • Naldi L, Peli L, Parazzini F. Association of early-stage psoriasis with smoking and male alcohol consumption: evidence from an Italian case-control study. Arch Dermatol1999; 135:1479–84.
  • Slopen N. et al.; Psychosocial stress and cigarette smoking persistence, cessation, and relapse over 9–10 years: a prospective study of middle-aged adults in the United States; Cancer Causes Control DOI 10.1007/s10552-013-0262-5